Study: PACS helps cut back on repeat imaging

A controversial article in the new issue of Health Affairs casts doubt on whether health information technology can help curb imaging utilization. But a new study suggests that at least one kind of computer technology, PACS, can help cut back on repeat imaging.

Normally, when patients transition between health care institutions, they carry the medical images from CT or MRI scans on CDs -- CDs which can be lost or damaged, and which doctors often find a hassle to use because of slow CD-ROM speeds or unfamiliar viewing interfaces. Partly because of this, patients are sometimes re-scanned when they arrive at the new hospital or facility, needlessly raising health care costs and often exposing the patients to more ionizing radiation.

But a retrospective study published this month in the American Journal of Roentgenology says that uploading patients' scans into a PACS system can help reduce repeat imaging. In fact, in the study, patients who brought CDs to a hospital but whose images weren't uploaded into the PACS were five times more likely to get a repeat MR or CT scan than those whose images were brought online.

"Importing outside images to PACS appears to reduce the rate of repeat imaging at the transfer of care between institutions. Other institutions should consider importing outside images to PACS," wrote the researchers, led by Michael T. Lu with the University of California, San Francisco.

For the study, the researchers examined the records of 124 patients with liver cancer who had had a CT or MR scan at an outside institution within the last four months, before getting transferred to UCSF for a cancer treatment called transarterial chemoembolization, which involves delivering chemo drugs directly to the liver through a catheter. This treatment generally first requires patients to get an MRI or multi-phase contrast-enhanced CT scan for adequate evaluation, the researchers said.

Before or during the transfer, some of the patients or their doctors sent CDs or films to the school's two hospitals, which were then uploaded to PACS by two film libraries staffed around the clock.

For patients who had outside film imaging that wasn't uploaded into the PACS, 52 percent (14 out of 27) underwent repeat imaging after transfer. But for patients whose images were uploaded, only 11 percent had repeat imaging (9 out of 79), similar to the figure (13 percent) for another group of patients who had all of their earlier imaging done in-house at UCSF (18 out of 143 patients).

The researchers said patients whose data weren't uploaded to the PACS were still more likely to undergo repeat imaging after controlling for confounding variables, such as age, gender, disease spread and lesion size.

However, they did note some limitations with their study. The researchers said they relied on electronic medical records to determine whether patients had brought in outside medical images, and that they weren't able to say why some outside images weren't imported to the hospital's PACS. Also, the patients sometimes require three-month surveillance imaging, which could justify a repeat scan but which was hard to identify in retrospective reports, the researchers said.

The study, "Reducing the Rate of Repeat Imaging: Import of Outside Images
to PACS," was conducted from January 2006 through June 2009.